Systems and methods for improved stability of electrochemical sensors
First Claim
1. A method for determining a concentration of an analyte in a sample, the method comprising:
- introducing a sample including an analyte into an electrochemical cell of a sample analyzing device to cause a transformation of the analyte, the electrochemical cell having a first electrode and a second electrode;
determining a measurement of a parameter correlating to a physical property of the electrochemical cell, said parameter comprising a measured capacitance of the electrochemical cell;
calculating a correction factor, wherein said correction factor is in view of at least said parameter; and
determining a first analyte concentration and a corrected concentration of the analyte in view of the correction factor, wherein determining said measured capacitance of the electrochemical cell further comprises;
applying a first test voltage between the first electrode and the second electrode after the presence of sample has been detected in the test strip for a first time interval to determine whether sample or a control solution has been introduced into the test strip;
applying a second test voltage between the first electrode and the second electrode for a second time interval sufficient to oxidize a reduced mediator at the second electrode, the second test voltage having a higher absolute magnitude than that of the first test voltage, the second test voltage having an AC voltage component and a DC voltage component, the AC voltage component being applied at a predetermined amount of time after the application of the second test voltage, the DC voltage component having a magnitude to cause a limiting test current at the second electrode, the second electrode not having a reagent layer coating;
applying a third test voltage between the first electrode and the second electrode for a third time interval following the application of the second test voltage sufficient to oxidize a reduced mediator at the first electrode; and
processing a portion of the test currents, resulting from the AC voltage component, into a capacitance value,and in which the first analyte concentration is calculated based on test current values during the second time interval and the third time interval and the corrected analyte concentration is calculated based on the first analyte concentration and the correction factor.
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Accused Products
Abstract
Methods for determining a concentration of an analyte in a sample, and the devices and systems used in conjunction with the same, are provided herein. In one exemplary embodiment of a method for determining a concentration of an analyte in a sample, a sample including an analyte is provided in a sample analyzing device having a working and a counter electrode. An electric potential is applied between the electrodes and a measurement of a parameter correlating to changes in a physical property of the sample analyzing device is calculated. A concentration of the analyte in view of the parameter correlating to a change in the physical property can then be determined Systems and devices that take advantage of the parameter correlating to changes in a physical property to make analyte concentration determinations are also provided.
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Citations
20 Claims
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1. A method for determining a concentration of an analyte in a sample, the method comprising:
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introducing a sample including an analyte into an electrochemical cell of a sample analyzing device to cause a transformation of the analyte, the electrochemical cell having a first electrode and a second electrode; determining a measurement of a parameter correlating to a physical property of the electrochemical cell, said parameter comprising a measured capacitance of the electrochemical cell; calculating a correction factor, wherein said correction factor is in view of at least said parameter; and determining a first analyte concentration and a corrected concentration of the analyte in view of the correction factor, wherein determining said measured capacitance of the electrochemical cell further comprises; applying a first test voltage between the first electrode and the second electrode after the presence of sample has been detected in the test strip for a first time interval to determine whether sample or a control solution has been introduced into the test strip; applying a second test voltage between the first electrode and the second electrode for a second time interval sufficient to oxidize a reduced mediator at the second electrode, the second test voltage having a higher absolute magnitude than that of the first test voltage, the second test voltage having an AC voltage component and a DC voltage component, the AC voltage component being applied at a predetermined amount of time after the application of the second test voltage, the DC voltage component having a magnitude to cause a limiting test current at the second electrode, the second electrode not having a reagent layer coating; applying a third test voltage between the first electrode and the second electrode for a third time interval following the application of the second test voltage sufficient to oxidize a reduced mediator at the first electrode; and processing a portion of the test currents, resulting from the AC voltage component, into a capacitance value, and in which the first analyte concentration is calculated based on test current values during the second time interval and the third time interval and the corrected analyte concentration is calculated based on the first analyte concentration and the correction factor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for measuring a corrected analyte concentration, the method comprising:
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applying a sample containing an analyte to a test strip; applying to the sample a first test voltage for a first time interval between a first electrode and a second electrode after the presence of sample has been detected in the test strip to determine whether sample or a control solution has been introduced into the test strip; applying to the sample a second test voltage for a second time interval between the first electrode and the second electrode sufficient to oxidize a reduced mediator at the second electrode and having a higher absolute magnitude than that of the first test voltage; following the application of the second test voltage, applying to the sample a third test voltage for a third time interval between the first electrode and the second electrode sufficient to oxidize the reduced mediator at the first electrode; calculating a first analyte concentration in the sample based on test current values during the second time interval and the third time interval; determining a capacitance of the test strip; and calculating a capacitance corrected analyte concentration based on the first analyte concentration and the capacitance wherein said determining a capacitance of the test strip further comprises; applying the second test voltage between the first electrode and the second electrode, the second test voltage having an AC voltage component and a DC voltage component, the AC voltage component being applied at a predetermined amount of time after the application of the second test voltage, the DC voltage component having a magnitude sufficient to cause a limiting test current at the second electrode, the second electrode not having a reagent layer coating; and processing a portion of the test currents, resulting from the AC voltage component, into a capacitance value. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification